1. Field of the Invention
The present invention relates to an electromagnetic wave shield and, more particularly, to an integrated plastic shield suitable for shielding the electromagnetic waves of a cathode ray tube usable with a display device.
2. Background Art
The recent trend of enlarging monitors and improving the resolution of monitors has resulted in the generation of a large amount of electromagnetic waves by the cathode ray tubes used in the newer monitors. Such electromagnetic waves sometimes cause interference in electronic equipment around the monitor, thus causing operational errors in nearby electronic equipment. Additionally, electromagnetic waves from the cathode ray tube can be injurious to one's health, thus the amount of electromagnetic waves discharged into the atmosphere should be kept to a minimum level. In order to limit the amount of discharged electromagnetic waves, various types of shields may be used with monitors.
An electromagnetic shield is comprised of highly conductive metal sheets that are formed through a pressing process prior to being integrated into a predetermined configuration through a fastening process. That is, 15 to 30 metal sheets have to be assembled into a shield using a plurality of fasteners, thus complicating the production process of the shield. In addition, the elements of the typical shield are formed of 3 to 5 different kinds of materials. This handling of various components of various materials reduces production efficiency due to a more complicated assembling process to combine the necessary elements into a shield. When a monitor is being assembled, it is necessary to first connect a degaussing coil to the shield prior to mounting the shield onto the cathode ray tube. This further reduces the manufacturing productivity during the production process of monitors. The degaussing coils are connected to the shield to prevent the reduction of image quality due to the electromagnetic waves of the cathode ray tube. Terminals are located on the cathode ray tube to ground the shield, but they are also problematic because the terminals increase the number of different materials used with the shield and reduce the grounding effect of the shield due to non ideal contact between the terminals and the cathode ray tube. High voltage current flows through the degaussing coil that may be connected to the shield using fixing members integrated with the metal sheets or by using separate cable ties. The electromagnetic shield may be constructed of metal sheets giving the shield many sharpened edges that may cause unexpected damage to the covered coils. When the covered coils are unexpectedly damaged by the sharpened edges of the shield, they may short circuit and cause serious damage to the monitor.
Contemporary electromagnetic shields are time consuming to assemble, involve various components, can cause gouges in the tape used to cover degaussing coils, and are not easily recyclable due to the multitude of different materials used in the constructing an electromagnetic shield. I believe that it may be possible to improve the current art by providing an electromagnetic wave shield that is formed of a single structure, that has a simpler assembly process, that does not generate noise when the cathode ray tube is magnetized by a degaussing coil, that does not have any sharp edges, that has improved durability, that increases the efficiency of production, that can be produced more economically, that is conveniently recyclable, and that is suitable for use in monitors.